Evaluating convolutional neural network-enhanced electrocardiography for hypertrophic cardiomyopathy detection in a specialized cardiovascular setting

The efficacy of convolutional neural network (CNN)-enhanced electrocardiography (ECG) in detecting hypertrophic cardiomyopathy (HCM) and dilated HCM (dHCM) remains uncertain in real-world applications. This retrospective study analyzed data from 19,170 patients (including 140 HCM or dHCM) in the Shinken Database (2010-2017). We evaluated the sensitivity, positive predictive rate (PPR), and F1 score of CNN-enhanced ECG in a ''basic diagnosis'' model (total disease label) and a ''comprehensive diagnosis'' model (including disease subtypes). Using all-lead ECG in the "basic diagnosis" model, we observed a sensitivity of 76%, PPR of 2.9%, and F1 score of 0.056. These metrics improved in cases with a diagnostic probability of ≥ 0.9 and left ventricular hypertrophy (LVH) on ECG: 100% sensitivity, 8.6% PPR, and 0.158 F1 score. The ''comprehensive diagnosis'' model further enhanced these figures to 100%, 13.0%, and 0.230, respectively. Performance was broadly consistent across CNN models using different lead configurations, particularly when including leads viewing the lateral walls. While the precision of CNN models in detecting HCM or dHCM in real-world settings is initially low, it improves by targeting specific patient groups and integrating disease subtype models. The use of ECGs with fewer leads, especially those involving the lateral walls, appears comparably effective.

The Characteristics of Primary Retrograde Approach Selection for Native Coronary Chronic Occlusion With Short Occlusion Length from the Japanese CTO-PCI Expert Registry

Although the coronary chronic total occlusion (CTO) crossing algorithm has been published, the characteristics associated with the first strategy selection for short-length lesions <20 mm is still debatable. This study aimed to determine the characteristics associated with primary retrograde approach (PRA) for native CTO with short occlusion length in percutaneous coronary intervention (PCI). Between January 2014 and December 2021, we examined data on 4,088 lesions in the Japanese CTO-PCI Expert Registry with occlusion lengths <20 mm. Then, the characteristics for short-length CTO, which was performed by way of the PRA, were assessed. PRA was performed in 785 patients (19.2%). The guidewire success rate was 93.6%, and the technical success rate was 91.3%. Previous coronary artery bypass grafting, chronic kidney disease, and 6 lesion/anatomic characteristics (i.e., blunt stump, distal runoff <1 mm, CTO lesion tortuosity, reattempt procedures, ostial location, and the presence of collateral channel grade 2) were associated with PRA (p <0.05). Moreover, hemodialysis was an independent factor of unsuccessful anterograde guidewire crossing, along with distal runoff <1 mm, the existence of calcification, and CTO lesion tortuosity (all p <0.05). In clinical settings, these independent factors for PRA in short-length CTO can help in selecting the CTO-PCI strategy.

Retrograde Coronary Chronic Total Occlusion Intervention (JR-CTO) Score: From the Japanese CTO-PCI Expert Registry

BACKGROUND

Despite the effectiveness of the retrograde approach for chronic total occlusion (CTO) lesions, there are no standardized tools to predict the success of retrograde percutaneous coronary intervention (PCI).

OBJECTIVES

The objective of this study was to develop a prediction tool to identify CTO lesions that will achieve successful retrograde PCI.

METHODS

This study evaluated data from 2,374 patients who underwent primary retrograde CTO-PCI and were enrolled in the Japanese CTO-PCI Expert Registry between January 2016 and December 2022 (NCT01889459). All observations were randomly assigned to the derivation and validation cohorts at a 2:1 ratio. The prediction score for guidewire failure in retrograde CTO-PCI was determined by assigning 1 point for each factor and summing all accrued points.

RESULTS

The JR-CTO score (moderate-severe calcification, tortuosity, Werner collateral connection grade ≤1, and nonseptal collateral channel) demonstrated a C-statistic for guidewire failure of 0.72 (95% CI: 0.67-0.76) and 0.71 (95% CI: 0.64-0.77) in the derivation and validation cohorts, respectively. Patients with lower scores had higher guidewire and technical success rates and decreased guidewire crossing time and procedural time (P < 0.01).

CONCLUSIONS

The JR-CTO (Japanese Retrograde Chronic Total Occlusion) score, a simple 4-item score that predicts successful guidewire crossing in patients undergoing retrograde CTO-PCI, has the potential to support clinical decision-making for the retrograde approach.

Lead-Specific Performance for Atrial Fibrillation Detection in Convolutional Neural Network Models Using Sinus Rhythm Electrocardiography

Background: We developed a convolutional neural network (CNN) model to detect atrial fibrillation (AF) using the sinus rhythm ECG (SR-ECG). However, the diagnostic performance of the CNN model based on different ECG leads remains unclear. Methods and Results: In this retrospective analysis of a single-center, prospective cohort study, we identified 616 AF cases and 3,412 SR cases for the modeling dataset among new patients (n=19,170). The modeling dataset included SR-ECGs obtained within 31 days from AF-ECGs in AF cases and SR cases with follow-up ≥1,095 days. We evaluated the CNN model's performance for AF detection using 8-lead (I, II, and V1-6), single-lead, and double-lead ECGs through 5-fold cross-validation. The CNN model achieved an area under the curve (AUC) of 0.872 (95% confidence interval (CI): 0.856-0.888) and an odds ratio of 15.24 (95% CI: 12.42-18.72) for AF detection using the eight-lead ECG. Among the single-lead and double-lead ECGs, the double-lead ECG using leads I and V1 yielded an AUC of 0.871 (95% CI: 0.856-0.886) with an odds ratio of 14.34 (95% CI: 11.64-17.67). Conclusions: We assessed the performance of a CNN model for detecting AF using eight-lead, single-lead, and double-lead SR-ECGs. The model's performance with a double-lead (I, V1) ECG was comparable to that of the 8-lead ECG, suggesting its potential as an alternative for AF screening using SR-ECG.

New Angiographic Difficulty Score for First-Attempt Chronic Total Occlusion in the 3 Major Coronary Arteries

BACKGROUND

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is still challenging due to complex lesion morphology. Success rates may vary among the 3 major coronary arteries, influenced by clinical and angiographic characteristics.

OBJECTIVES

This study sought to evaluate the differences in the predictors of unsuccessful PCI in first-attempt CTO lesions of the 3 major coronary arteries compared with the J-CTO (Japanese CTO) score.

METHODS

This study assessed 6,408 first-attempt CTO patients from the Japanese CTO-PCI expert registry between January 2014 and December 2021, randomly assigned to derivation and validation sets. Difficulty scores for each artery were determined by assigning points to predictive unsuccessful factors.

RESULTS

The CTO lesions were distributed as follows: left anterior descending coronary artery: 2,245 (35%), left circumflex coronary artery: 1,131 (18%), and right coronary artery (RCA): 3,032 (47%). Regarding success rates, left circumflex coronary artery CTO had the lowest procedural success rate (90%) followed by RCA CTO (92%) and left anterior descending coronary artery CTO (94%). RCA CTO was significantly longer and more severely angulated, requiring more often the retrograde approach. A multivariate logistic analysis revealed that predictors of failed PCI were different in CTO lesions among the 3 major coronary arteries, respectively. Moreover, our difficulty score for RCA CTO was superior to the J-CTO score in predicting unsuccessful PCI.

CONCLUSIONS

Clinical and angiographic differences might explain the discrepancies of success rates in CTO lesions among the 3 major coronary arteries. Our novel difficulty score was comparable to the J-CTO score in predicting unsuccessful CTO-PCI with a superior discriminatory capacity.

Impact of minimum contrast media volumes during percutaneous coronary intervention for chronic total occlusion lesion

Contrast media exposure is associated with contrast-induced nephropathy (CIN) following percutaneous coronary intervention (PCI) of chronic total occlusion (CTO). Aim of this study is to assess the utility of minimum contrast media volume (CMV ≤ 50 mL) during CTO-PCI for CIN prevention in patients with chronic kidney disease (CKD). We extracted data from the Japanese CTO-PCI expert registry; 2863 patients with CKD who underwent CTO-PCI performed from 2014 to 2020 were divided into two groups: minimum CMV (n = 191) and non-minimum CMV groups (n = 2672). CIN was defined as an increased serum creatinine level of ≥ 25% and/or ≥ 0.5 mg/dL compared with baseline levels within 72 h of the procedure. In the minimum CMV group, the CIN incidence was lower than that in the non-minimum CMV group (1.0% vs. 4.1%; p = 0.03). Patient success rate was higher and complication rate was lower in the minimum CMV group than in the non-minimum CMV group (96.8% vs. 90.3%; p = 0.02 and 3.1% vs. 7.1%; p = 0.03). In the minimum CMV group, the primary retrograde approach was more frequent in the case of J-CTO = 1,2 and 3-5 groups compared to that in non-minimum CMV-PCI group (J-CTO = 0; 11% vs. 17.7%, p = 0.06; J-CTO = 1; 22% vs. 35.8%, p = 0.01; J-CTO = 2; 32.4% vs. 46.5%, p = 0.01; and J-CTO = 3-5; 44.7% vs. 80.0%, p = 0.02). Minimum CMV-PCI for CTO in CKD patients could reduce the incidence of CIN. The primary retrograde approach was observed to a greater extent in the minimum CMV group, especially in cases of difficult CTO.

Identification of patients with dilated phase of hypertrophic cardiomyopathy using a convolutional neural network applied to multiple, dual, and single lead electrocardiograms

Background

This study sought to develop an artificial intelligence-derived model to detect the dilated phase of hypertrophic cardiomyopathy (dHCM) on digital electrocardiography (ECG) and to evaluate the performance of the model applied to multiple-lead or single-lead ECG.

Methods

This is a retrospective analysis using a single-center prospective cohort study (Shinken Database 2010-2017, n = 19,170). After excluding those without a normal P wave on index ECG (n = 1,831) and adding dHCM patients registered before 2009 (n = 39), 17,378 digital ECGs were used. Totally 54 dHCM patients were identified of which 11 diagnosed at baseline, 4 developed during the time course, and 39 registered before 2009. The performance of the convolutional neural network (CNN) model for detecting dHCM was evaluated using eight-lead (I, II, and V1-6), single-lead, and double-lead (I, II) ECGs with the five-fold cross validation method.

Results

The area under the curve (AUC) of the CNN model to detect dHCM (n = 54) with eight-lead ECG was 0.929 (standard deviation [SD]: 0.025) and the odds ratio was 38.64 (SD 9.10). Among the single-lead and double-lead ECGs, the AUC was highest with the single lead of V5 (0.953 [SD: 0.038]), with an odds ratio of 58.89 (SD:68.56).

Conclusion

Compared with the performance of eight-lead ECG, the most similar performance was achieved with the model with a single V5 lead, suggesting that this single-lead ECG can be an alternative to eight-lead ECG for the screening of dHCM.

Machine Learning for Prediction of Technical Results of Percutaneous Coronary Intervention for Chronic Total Occlusion

(1) Background: The probability of technical success in percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) represents essential information for specifying the priority of PCI for treatment selection in patients with CTO. However, the predictabilities of existing scores based on conventional regression analysis remain modest, leaving room for improvements in model discrimination. Recently, machine learning (ML) techniques have emerged as highly effective methods for prediction and decision-making in various disciplines. We therefore investigated the predictability of ML models for technical results of CTO-PCI and compared their performances to the results from existing scores, including J-CTO, CL, and CASTLE scores. (2) Methods: This analysis used data from the Japanese CTO-PCI expert registry, which enrolled 8760 consecutive patients undergoing CTO-PCI. The performance of prediction models was assessed using the area under the receiver operating curve (ROC-AUC). (3) Results: Technical success was achieved in 7990 procedures, accounting for an overall success rate of 91.2%. The best ML model, extreme gradient boosting (XGBoost), outperformed the conventional prediction scores with ROC-AUC (XGBoost 0.760 [95% confidence interval {CI}: 0.740-0.780] vs. J-CTO 0.697 [95%CI: 0.675-0.719], CL 0.662 [95%CI: 0.639-0.684], CASTLE 0.659 [95%CI: 0.636-0.681]; p < 0.005 for all). The XGBoost model demonstrated acceptable concordance between the observed and predicted probabilities of CTO-PCI failure. Calcification was the leading predictor. (4) Conclusions: ML techniques provide accurate, specific information regarding the likelihood of success in CTO-PCI, which would help select the best treatment for individual patients with CTO.

Association between serum alkaline phosphatase and cardiovascular events in patients with atrial fibrillation

High alkaline phosphatase (ALP) levels are reported to be associated with an increased risk of cardiovascular events in patients with chronic kidney disease (CKD). Given the pathological link with CKD, a similar relationship may exist in patients with atrial fibrillation (AF). We retrospectively evaluated 1,719 patients with AF and normal hepatic function who were registered in the Shinken Database between November 2011 and March 2017. Study patients were divided into three groups according to ALP value tertiles with cut-offs of 175 and 227 IU/L (normal range: 95-350 IU/L). Each group's incidence rate was recorded, and the risks of cardiovascular events and each component for patients in the middle and high ALP tertiles were compared with those in the low tertile and evaluated using Cox regression models. The additional predictive value of the high ALP tertile over the existing risk scores for the components of cardiovascular events was evaluated via receiver operating characteristic (ROC) curve analysis. During the median follow-up of 731 days (IQR: 444-1095 days), 137 cardiovascular events occurred, with incidence rates of 2.94%, 3.44%, and 6.19%/person-year for the low, middle, and high ALP tertiles, respectively. Of these cardiovascular events, heart failure had the highest incidence rates (1.34%, 1.89%, and 4.29%/person-year for the low, middle, and high ALP tertiles, respectively) and the incidence rates of the other components of cardiovascular event were similar in each ALP groups. Multivariate Cox regression analysis yielded hazard ratios of 1.22 (95% confidence interval [CI] 0.70-1.96) and 1.62 (95% CI 1.06-2.48) for cardiovascular events and 1.66 (95% CI 0.87-3.15) and 2.50 (95% CI 1.39-4.48) for heart failure admission in the middle and high ALP tertiles, respectively. By ROC curve analysis for heart failure admission showed that the high ALP tertile lacked significant additive predictive value over the existing risk scores. High serum ALP levels, even those in the normal range, were significantly associated with an increased risk of cardiovascular events, especially heart failure admission in patients with AF.

Impact of Timing and Treatment Strategy on Coronary Perforation During Percutaneous Coronary Intervention for Chronic Total Occlusion

Coronary perforations during chronic total occlusion percutaneous coronary intervention (CTO-PCI) are potential complications and reportedly associated with adverse events. This study aimed to describe the clinical characteristics and timing of perforations during CTO-PCI. Data from the Japanese CTO-PCI expert registry included 8,760 patients who underwent CTO-PCI between January 2014 and January 2019. The major adverse cardiac and cerebrovascular events were defined as death, tamponade, myocardial infarction, stent thrombosis, stroke, and revascularization. The guidewire manipulation time was defined as the time required to cross the CTO without perforation. Among these patients, 333 (3.8%) developed perforation during the CTO crossing attempt. Of the 333 patients, 29 developed cardiac tamponades (8.7%). Perforations more frequently occurred in a retrograde wiring than in an anterograde wiring (6.6% vs 1.7%, p <0.0001). A longer guidewire manipulation time was associated with the occurrence of perforation (median 101 minutes [interquartile range 59 to 150 minutes] in the perforation group vs 54.9 minutes [interquartile range 21.1 to 112.7 minutes] in the nonperforation group, p <0.0001). Risk factors for perforation were age, history of coronary bypass graft, right coronary artery lesion, de novo lesion, use of a stiff guidewire, and guidewire manipulation time of >60 minutes during anterograde wiring and age, non-left anterior descending artery lesion, use of a polymer-jacketed guidewire, and use of epicardial channel during retrograde wiring. In conclusion, risk factors for perforation were different between anterograde and retrograde wirings. A prolonged guidewire manipulation time was associated with the occurrence of perforation, especially during anterograde wiring.

Procedural results and in-hospital outcomes of percutaneous coronary intervention for chronic total occlusion in patients with reduced left ventricular ejection fraction: Sub-analysis of the Japanese CTO-PCI Expert Registry

OBJECTIVES

To evaluate the procedural results and in-hospital outcomes of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) in patients with reduced left ventricular ejection fraction (LVEF).

BACKGROUND

While the technical success of general CTO-PCI has improved, CTO-PCI patients with reduced LVEF remain at high-risk for adverse events.

METHODS

The data of 820 patients with LVEF ≤ 35% (Group 1), 1816 patients with LVEF = 35%-50% (Group 2), and 5503 patients with LVEF ≥ 50% (Group 3), registered in the Japanese CTO-PCI Expert Registry from January 2014 to December 2019, were retrospectively analyzed. The primary endpoint was in-hospital major adverse cardiac or cerebrovascular events (MACCEs), including death, myocardial infarction, stent thrombosis, stroke, and emergent revascularization. Secondary endpoints included procedural details, guidewire success, and technical success.

RESULTS

There were no differences in guidewire and technical success rates between the groups. In-hospital MACCEs was significantly higher in Group 1 (Group 1 vs. Group 2 vs. Group 3: 3.4% vs. 1.7% vs. 1.5%, p = 0.001) and was especially driven by death (1.3% vs. 0.3% vs. 0.1%, p < 0.001) and stroke (0.7% vs. 0.2% vs. 0.2%, p = 0.007). Multivariate analysis showed that LVEF ≤ 35% (odds ratio [OR]; 1.58, 95% confidence interval [CI]; 1.04-2.41, p = 0.03) and New York Heart Association (NYHA) class ≥ 3 (OR; 2.01, 95% CI; 1.03-3.93, p = 0.04) were predictors of in-hospital MACCEs.

CONCLUSIONS

In-hospital MACCEs were significantly higher in patients with LVEF ≤ 35%. LVEF ≤;35% and NYHA class ≥ 3 were predictors of in-hospital MACCEs after CTO-PCI.

Identifying risk patterns in older adults with atrial fibrillation by hierarchical cluster analysis: A retrospective approach based on the risk probability for clinical events

•

In older AF patients, representative AF-related outcomes compete, causing difficulty in decision making.

•

We proposed cluster analysis using risk probability for four AF-related outcomes.

•

Older adults with AF were classified into 3 clusters.

•

The clusters could possibly identify older adults with AF with good/poor responses to AF-related treatment.

Background

Older adults with atrial fibrillation (AF) have highly diverse risk levels for mortality, heart failure (HF), thromboembolism (TE), and major bleeding (MB), thus an integrated risk-pattern algorithm is warranted.

Methods

We analyzed 573 AF patients aged ≥ 75 years from our single-center cohort (Shinken Database 2010–2018). The 3-year risk scores (risk probability) for mortality (M-score), HF (HF-score), TE (TE-score), and MB (MB-score) were estimated for each patient by logistic regression analysis. Using the four risk scores, cluster analysis was performed with Ward’s linkage hierarchical algorithm.

Results

Three clusters were identified: Clusters 1 (n = 429, 74%), 2 (n = 24, 5%), and 3 (n = 120, 21%). The clusters were characterized as standard risk (Cluster 1), high TE- and MB-risk (Cluster 2), and high M- and HF-risk (Cluster 3). Oral anticoagulants were prescribed for over 80% of the patients in each cluster. Catheter ablation for AF was performed only in Cluster 1 (8.9%). Compared with Cluster 1, Cluster 2 was more closely associated with males, asymptomatic AF, history of cerebral infarction or transient ischemic attack, history of intracranial hemorrhage, high HAS-BLED score (≥3), and low body mass index (<18.0 kg/m²). Cluster 3 was more closely associated with old age, heart failure, and low estimated creatinine clearance (<30 mL/min).

Conclusion

The cluster analysis identified those at a high risk for all-cause death and HF or a high risk for TE and MB and could support decision making in older adults with AF.

Occlusion patterns, strategies and procedural outcomes of percutaneous coronary intervention for in-stent chronic total occlusion

BACKGROUND

In-stent chronic total occlusion (CTO) presents various occlusion patterns, which complicate percutaneous coronary intervention (PCI).

AIMS

The aim of the study was to investigate the initial outcome and strategy of PCI for in-stent CTO according to the angiographic occlusion patterns.

METHODS

This study assessed 791 in-stent CTOs from the Japanese CTO-PCI Expert Registry from 2015 to 2018. They were divided into four patterns: pattern A (n=419), CTO within the stent segment; pattern B (n=196), CTO beyond the distal edge; pattern C (n=85), CTO beyond the proximal edge; and pattern D (n=69) CTO beyond both the proximal and distal edges.

RESULTS

There were significant differences in the technical success rates (96.2%, 86.2%, 92.9%, and 75.4% for patterns A-D, respectively; p<0.001), guidewire crossing times (22 [interquartile range: 10-46], 52 [24-102], 40 [20-78], and 86 [45-127] min, respectively; p<0.001), and the rates of antegrade approach alone (90.9%, 61.2%, 67.1%, and 31.9%, respectively; p<0.001).

CONCLUSIONS

PCI for CTO within the stent segment was associated with excellent initial outcomes with the antegrade approach. However, PCI for CTO beyond both the proximal and distal edges was associated with the poorest outcomes, even with the bidirectional approach.

Association between number of medications and mortality among older adult patients in a specialized cardiology hospital

AIM

Although polypharmacy has been associated with poor clinical outcomes, whether taking an increased number of medications is harmful or beneficial for older adult patients treated for cardiovascular diseases might require further discussion.

METHODS

We analyzed data of 2089 patients aged ≥75 years in a single hospital-based cohort. The study population was divided into three groups according to the tertiles of the number of medications at baseline: <3 (n = 647), 3-7 (n = 707) and ≥8 (n = 735).

RESULTS

The cumulative incidences of all-cause death at 3 years among patients taking less than three, three to seven and eight or more medications were 3.7%, 4.1% and 7.8%, respectively (log-rank test P = 0.015). In a Cox regression analysis, taking eight or more total medications (vs 0-2) was independently associated with all-cause death (hazard ratio 1.67, 95% CI 1.01-2.78). For predicting mortality using the number of medications, the maximum Youden Index was 7. In subgroups with certain heart diseases, no regular tendency of an increase in the risk of all-cause death was observed with an increase in the number of medications.

CONCLUSIONS

The number of medications taken was independently associated with mortality among older adult patients, with a relatively high cut-off point. This association was not observed in patients with certain heart diseases, possibly indicating the merit - rather than the harm - of medical treatment in the cardiovascular field. Geriatr Gerontol Int 2021; 21: 985-995.

Relationship between number of medications and incidence of falls or bone fracture in elderly patients with non-valvular atrial fibrillation: Shinken database analysis

AIM

Polypharmacy is known to be a risk factor for falls or bone fracture (F/F) in elderly patients. However, this relationship is not fully described in patients with non-valvular atrial fibrillation (NVAF), for which F/F may lead to serious clinical outcomes, including major bleeding.

METHODS

We analyzed 509 elderly (aged ≥75 years) patients with NVAF who had recently visited a hospital specializing in cardiology, of which 272 patients had paroxysmal atrial fibrillation (PAF) and 237 had persistent/permanent atrial fibrillation (PeAF). Patients were divided into four groups according to the number of medications: ≤3, 4-6, 7-9, and ≥10. The relationship between the number of medications and incidence rate of F/F in AF patients was analyzed. In addition, this relationship was analyzed in patients with each AF type.

RESULTS

Cumulative incidence of F/F at 3 years in the respective categories was 3.7%, 5.4%, 4.3% and 5.7% for PAF, and 5.2%, 7.5%, 7.8% and 25.0% for PeAF (log-rank test, P = 0.930 and 0.003, respectively). In a multivariable model, patients with ≥10 medications showed a significantly higher risk for F/F compared with those with ≤3 medications as reference only in PeAF (adjusted hazard ratio 4.82, 95%CI 1.42-16.33), without significant interaction (P = 0.081).

CONCLUSIONS

Elderly NVAF patients using ≥10 medications showed a higher risk for F/F. In subgroup analysis, this association was observed only in patients with PeAF, although there was no significant interaction between number of medications and AF type. Geriatr Gerontol Int 2021; 21: 802-809.

Predictors of prolonged guidewire manipulation time for native coronary chronic total occlusion percutaneous coronary intervention via primary antegrade approach

OBJECTIVES

This study aimed to identify the predictive factors for the guidewire manipulation time (GWMT) of ≥20 and 30 min for chronic total occlusion-percutaneous coronary intervention (CTO-PCI) via the primary antegrade approach (PAA).

BACKGROUND

Selection of primary retrograde approach (PRA) and the optimal timing to switch from antegrade to retrograde approach for coronary CTO-PCI is still debatable.

METHODS

Using the Japanese CTO-PCI expert registry data, we selected and analyzed 4461 patients who underwent CTO-PCI via PAA alone. The considerable lesion/anatomical factors for GWMT ≥20 and 30 min were analyzed. The risks of prolonged GWMT ≥20 and 30 min were stratified as easy, intermediate, difficult, and very difficult according to the multivariate analysis.

RESULTS

Nine lesion/anatomical characteristics (blunt stump, side branch at proximal cap, bifurcation at the exit point, calcification, tortuosity, occlusion length ≥ 20 mm, reattempt, nonleft anterior descending artery (nonleft anterior descending artery [LAD]), and tandem CTO) were independent predictors of GWMT ≥20 min (all p < 0.05). Excluding the nonLAD and tandem CTO, the same factors of GWMT ≥20 min correlated with GWMT ≥30 min (all p < 0.05). The distributions were increased in easy, intermediate, difficult, and very difficult subsets of GWMT ≥20 min (58.3%, 77.2%, 89.1%, and 100%) and GWMT ≥30 min (47.5%, 69.2%, 83.9%, and 100%).

CONCLUSIONS

These predictive factors of prolonged GWMT should be assessed before CTO-PCI via PAA and when considering an adequate timing to switch the retrograde or PRA if clinically available.

Relationship between resting 12-lead electrocardiogram and all-cause death in patients without structural heart disease: Shinken Database analysis

Background

Resting 12-lead electrocardiography is widely used for the detection of cardiac diseases. Electrocardiogram readings have been reported to be affected by aging and, therefore, can predict patient mortality.

Methods

A total of 12,837 patients without structural heart disease who underwent electrocardiography at baseline were identified in the Shinken Database among those registered between 2010 and 2017 (n = 19,170). Using 438 electrocardiography parameters, predictive models for all-cause death and cardiovascular (CV) death were developed by a support vector machine (SVM) algorithm.

Results

During the observation period of 320.4 days, 55 all-cause deaths and 23 CV deaths were observed. In the SVM prediction model, the mean c-statistics of 10 cross-validation models with training and testing datasets were 0.881 ± 0.027 and 0.927 ± 0.101, respectively, for all-cause death and 0.862 ± 0.029 and 0.897 ± 0.069, respectively for CV death. For both all-cause and CV death, high values of permutation importance in the ECG parameters were concentrated in the QRS complex and ST-T segment.

Conclusions

Parameters acquired from 12-lead resting electrocardiography could be applied to predict the all-cause and CV deaths of patients without structural heart disease. The ECG parameters that greatly contributed to the prediction were concentrated in the QRS complex and ST-T segment.

Decline in eGFR over time and incidence of cardiovascular events: Shinken database analysis

BACKGROUND

It has been reported that a large decline in estimated glomerular filtration rate (eGFR) over time is associated with increased incidence of cardiovascular disease. We investigated whether this association differs according to the baseline eGFR.

METHODS

A total of 4666 patients (male 71%) with measurements of eGFR at both baseline and 1 year and that had no cardiovascular events at 1-year follow-up were retrieved from the Shinken Database between June 2004 and March 2015. The study population was divided into three groups by baseline eGFR (mL/min/1.73 m²): high (≥60, n = 1650), intermediate (45-59, n = 1947), and low (<45, n = 1069) eGFR groups. Each eGFR group was further divided into two groups by eGFR slope (change at 1 year, <-10 and ≥-10 mL/min/1.73 m²). The patient characteristics and the incidences of cardiovascular events within 3 years (after 1-year follow-up) were compared between the negatively large eGFR slope (<-10) and others (≥-10) in each eGFR group.

RESULTS

A total of 187 cardiovascular events occurred during the mean follow-up of 2.8 ± 0.6 years. The adjusted hazard ratios of eGFR slope (<-10 with reference to ≥-10) were 2.37 (95% CI, 1.28-4.40), 3.10 (95% CI, 1.78-5.40), and 2.66 (95% CI, 1.15-6.13) in the high, middle, and low eGFR groups, respectively. Similar results were found in patients with structural heart disease, but not in those without.

CONCLUSIONS

Decline in eGFR was associated with an increase in cardiovascular events, and this effect was consistent regardless of the baseline eGFR.

Prediction of atrial fibrillation by 12-lead electrocardiogram parameters in patients without structural heart disease

Background

Recently, the analysis of electrocardiogram (ECG) waveform by artificial intelligence has been reported to pick out those who have atrial fibrillation (AF) or have a high potential of developing AF, which, however, cannot explain the mechanisms or algorisms for the prediction from its nature.

Purpose

The purpose of this study is to conduct a comprehensive analysis to investigate the difference of weighting in predicting capability for AF among hundreds of automatically-measured ECG parameters using a single ECG at sinus rhythm.

Methods and results

Out of Shinken Database 2010–2017 (n=19170), 12825 patients were extracted, where those with ECG showing AF rhythm at the initial visit (including all persistent/permanent AF and a part of paroxysmal AF) and those with structural heart diseases were excluded. Out of 639 automatically-measured ECG parameters in MUSE data management system (GE Healthcare, USA), 438 were used. [Analysis 1] A predicting model for paroxysmal AF were determined by logistic regression analysis (Total, n=12825; paroxysmal AF, n=1138), showing a high predictive capability (AUC = 0.780, p&lt;0.001). In this model, the relative contribution of ECG parameters (by coefficient of determination) according to the time phase were P:72.4%, QRS:32.7%, and ST-T:13.7%, respectively (Figure A). [Analysis 2] Excluding AF at baseline, a predicting model for new-developed AF were determined by Cox regression analysis (Total, n=11687; new-developed AF, n=87), showing a high predictive capability (AUC = 0.887, p&lt;0.001). In this model, the relative contribution of parameters (by log likelihood) according to the time phase were P:40.8%, QRS:42.5%, and ST-T:24.9%, respectively (Figure B).

Conclusions

We determined ECG parameters that potentially contribute to picking up existing AF or predicting future development of AF, where the measurement of P wave strongly contributed in the former whereas all time phases were similarly important in the latter.

Weighting of parameters to predict AF

Funding Acknowledgement

Type of funding source: Private hospital(s). Main funding source(s): Self funding of the institute

Heart rate recovery after exercise as a prognostic predictor in patients with atrial fibrillation

Background

A delayed heart rate recovery (HRR) after exercise is related to mortality in sinus rhythm. This study aimed to investigate this concept can be applied to patients with atrial fibrillation (AF).

Methods

We analyzed 483 patients with AF (mean 65 years, male 74%). HRR integral was calculated by integrating the difference in HR in every 3 second between the end of exercise and the specified time after the exercise (30, 60, 120 and 180 seconds). After evaluating the prognostic power of each HRR integral, we selected HRR integral of 180 seconds (180HRR-integral).

Results

We divided the patients into two groups using median value of 180HRR-integral. All-cause mortality, the incidence of cardiovascular events and heart failure events were higher in the poor 180HRR-integral. After adjustment for covariates, the impact of the high 180HRR-integral for all-cause mortality was 3.15 (p=0.057), 1.77 for cardiovascular events (p=0.067) and 1.28 for heart failure events (p=0.519).

Conclusion

Poor HRR was associated with worse prognosis in patients with AF.

Funding Acknowledgement

Type of funding source: None

Seasonal Variations in the Incidence of Ischemic Stroke, Extracranial and Intracranial Hemorrhage in Atrial Fibrillation Patients

BACKGROUND

Ischemic stroke (IS) and major bleeding, which are serious adverse events in patients with atrial fibrillation (AF), could have seasonal variations, but there are few reports.Methods and Results:In the Shinken Database 2004-2016 (n=22,018), 3,581 AF patients (average age, 63.5 years; 2,656 men, 74.2%; 1,388 persistent AF, 38.8%) were identified. Median CHADS₂and HAS-BLED scores were both 1 point. Oral anticoagulants were prescribed for 2,082 (58.1%) patients (warfarin, 1,214; direct oral anticoagulants [DOACs], 868). Incidence and observation period (maximum 3 years) of IS, extracranial hemorrhage (ECH), and intracranial hemorrhage (ICH) were counted separately for the northern hemisphere seasons. During the mean follow-up period of 2.4 years, there were totals of 90 IS, 73 ECH, and 33 ICH cases. The respective incidence rates per 1,000 patient-years in spring, summer, autumn, and winter were 8.5, 8.8, 7.5, and 16.8 for IS, 7.2, 9.7, 3.8, and 13.1 for ECH, and 2.7, 1.9, 3.8, and 7.0 for ICH. The number of patients with DOACs relatively increased among those with ECH in summer.

CONCLUSIONS

Significant seasonal variations were observed for IS, ECH, and ICH events in AF patients, and were consistently the highest in winter. A small peak of ECH was observed in summer, which seemed, in part, to be related to increased DOAC use.

Formation of Calcified Nodule as a Cause of Early In-Stent Restenosis in Patients Undergoing Dialysis

Background Dialysis is an independent risk factor for in-stent restenosis (ISR) after stent implantation in coronary arteries. However, the characteristics of ISR in patients undergoing dialysis remain unclear, as there are no histological studies evaluating the causes of this condition. The aim of the present study was to investigate the causes of ISR between patients who are undergoing dialysis and those who are not by evaluating tissues obtained from ISR lesions using directional coronary atherectomy. Methods and Results A total of 29 ISR lesions from 29 patients included in a multicenter directional coronary atherectomy registry of 128 patients were selected for analysis and divided into a dialysis group (n=8) and a nondialysis group (n=21). Histopathological evaluation demonstrated that an in-stent calcified nodule was a major histological characteristic of ISR lesions in the dialysis group and the prevalence of an in-stent calcified nodule was significantly higher in the dialysis group compared with the nondialysis group (75% versus 5%, respectively; P<0.01). On the other hand, the prevalence of an in-stent lipid-rich plaque was significantly lower in the dialysis group compared with the nondialysis group (0% versus 43%, respectively; P=0.03). In all cases with an in-stent calcified nodule, the underlying calcification before stent implantation was moderate to severe. When tissue characteristics were stratified according to duration post-stent implantation, an in-stent calcified nodule in the dialysis group was mainly observed within 1 year after stent implantation. Conclusions In-stent calcified nodules are a common cause of ISR in patients undergoing dialysis and are observed within 1 year after stent implantation, suggesting different causes of ISR between patients undergoing dialysis and those who are not.

Association between bisoprolol plasma concentration and worsening of heart failure: (CVI ARO 6)

BACKGROUND

Although bisoprolol has been established to prevent heart failure (HF), finding the optimal dose remains a challenge. It is crucial to understand the distribution of bisoprolol plasma concentration (Bis-PC) and association with outcomes.

METHODS

This was a single-center observational study in 114 HF patients under once-daily bisoprolol. After obtaining trough Bis-PC, patients were followed-up for 1 year. The primary endpoint was worsening of HF. Patients were divided according to the tertiles of Bis-PC.

RESULTS

In multivariate logistic regression analysis, independent predictors of high Bis-PC (1st tertile: ≥ 5.38 ng/mL) were age, eGFR, and bisoprolol dose. The cumulative incidence rates of the primary endpoint were 10.5%/13.2%/26.3% in low/middle/high Bis-PC categories, respectively (log rank test, p = 0.087). Bis-PC was independently associated with the primary endpoint (hazard ratio [HR], 1.19 [per ng/mL], 95% CI 1.03-1.36). In subgroups, high Bis-PC was independently associated with the primary endpoint in elderly (HR 6.32, 95% CI 1.34-29.83) and HF with preserved ejection fraction (HFpEF) (HR 3.52, 95% CI 1.06-11.70).

CONCLUSIONS

Bis-PC was increased by age and renal dysfunction, and high Bis-PC was associated with worsening of HF in elderly and HFpEF patients. Care should be taken to avoid overdose.

A Simple Formula for Predicting the Maintenance Dose of Warfarin with Reference to the Initial Response to Low Dosing at an Outpatient Clinic

Objective The pharmacodynamic effect of warfarin varies among individuals, and its maintenance dose is widely distributed. Although many formulae for predicting the maintenance dose of warfarin have been developed, most of them are complex and not in practical use. Methods and Materials Among 12,738 new patients visiting the Cardiovascular Institute between 2004 and 2009, we identified 127 patients (66.6±8.8 years, 89 men) with atrial fibrillation for whom warfarin was newly started with an initial dose of 2 mg/day and the international normalized ratio (INR) at 1 year after warfarin was started was within the therapeutic range. The prediction models for the maintenance dose were developed by an exponential equation and a first-order equation. Results The initial response of the INR to the dose of 2 mg/day (initial INR) ranged from 1.00-3.24 (mean 1.43), while the maintenance dose of warfarin ranged from 0.5-14 mg (mean 3.8 mg). The maintenance dose showed an exponential correlation to the initial INR: (predicted maintenance dose) =5.522× (initial INR) ^-1.556 (R²=0.795, p<0.001). Excluding the patients with a poor response to the initial dose (initial INR <1.1, n=32) permitted a simple correlation with a first-order approximation: (predicted maintenance dose) =-2.009× (initial INR) +6.172 (R²=0.706, p<0.001). Conclusion We developed a simple formula for predicting the maintenance dose of warfarin using the initial response of the INR to low-dose warfarin.

Assessment of reattempted percutaneous coronary intervention strategy for chronic total occlusion after prior failed procedures: Analysis of the Japanese CTO-PCI Expert Registry

OBJECTIVES

We aimed to investigate strategies for reattempted percutaneous coronary interventions (PCIs) for chronic total occlusions (CTOs) by highly skilled operators after a failed attempt.

BACKGROUND

Development of complex techniques and algorithms has been standardized for CTO-PCI. However, there is no appropriate strategy for CTO-PCI after a failed procedure.

METHOD

From 2014 to 2016, the Japanese CTO-PCI Expert Registry included 4,053 consecutive CTO-PCIs (mean age: 66.8 ± 10.9 years; male: 85.6%; Japanese CTO [J-CTO] score: 1.92 ± 1.15). Initial outcomes and strategies for reattempted CTO-PCIs were evaluated and compared with first-attempt CTO-PCIs.

RESULTS

Reattempt CTO-PCIs were performed in 820 (20.2%) lesions. The mean J-CTO score of reattempt CTO-PCIs was higher than that of first-attempt CTO-PCIs (2.86 ± 1.03 vs. 1.68 ± 1.05, p < .001). The technical success rate of reattempt CTO-PCIs was lower than that of first-attempt CTO-PCIs (86.7% vs. 90.8%, p < .001). Regarding successful CTO-PCIs, the strategies comprised antegrade alone (reattempt: 36.1%, first attempt: 63.8%), bidirectional approach (reattempt: 54.4%, first attempt: 30.3%), and antegrade approach following a failed bidirectional approach (reattempt: 9.4%, first attempt: 5.4%). Parallel wire technique, intravascular ultrasound guide crossing, and bidirectional approach technique were frequently performed in reattempt CTO-PCIs. Reattempt CTO-PCIs showed higher rates of myocardial infarction (2.1% vs. 0.9%, p < .001) and coronary perforation (6.9% vs. 4.2%, p = .002) than first-attempt CTO-PCIs.

CONCLUSIONS

The technical success rate of reattempt CTO-PCIs is lower than that of first-attempt CTO-PCIs. However, using more complex strategies, the success rate of reattempt CTO-PCI can be improved by highly skilled operators.

Myocardial bridging is an independent predictor of positive spasm provocation testing by intracoronary ergonovine injections: a retrospective observational study

The relationship between myocardial bridging (MB) and coronary spasms during spasm provocation testing (SPT) remains unclear. We aimed to investigate whether MB was correlated with the SPT by ergonovine (ER) injections in a retrospective observational study. Of the 3340 patients who underwent a first coronary angiography, 166 underwent SPT using ER injections and were divided into 2 groups: MB(+) (n = 23), and MB(−) (n = 143). MB was defined as an angiographic reduction in the diameter of the coronary artery during systole. The patients who had severe organic stenosis in the left anterior descending coronary artery were excluded. The MB(+) group more frequently had diabetes mellitus and chronic kidney disease, and a thicker interventricular septum thickness. The rate of SPT-positivity was higher in the MB(+) group than MB(−) group (56.5% vs. 22.4%, P = 0.001). A multivariate regression analysis showed that the presence of MB was independently associated with SPT-positivity (odds ratio 5.587, 95% confidence interval 2.061–15.149, P = 0.001). In conclusion, coronary spasms during provocation tests with ER independently correlated with the MB. MB may predict coronary spasms.

Comparison of risk models for mortality and cardiovascular events between machine learning and conventional logistic regression analysis

AIMS

Non-linear models by machine learning may identify different risk factors with different weighting in comparison to conventional linear models.

METHODS AND RESULTS

The analyses were performed in 15,933 patients included in the Shinken Database (SD) 2004-2014 (n = 22,022) for whom baseline data of blood sampling and ultrasound cardiogram and follow-up data at 2 years were available. Using non-linear models with machine learning software, 118 risk factors and their weighting of risk for all-cause mortality, heart failure (HF), acute coronary syndrome (ACS), ischemic stroke (IS), and intracranial hemorrhage (ICH) were identified, where the top two risk factors were albumin/hemoglobin, left ventricular ejection fraction/history of HF, history of ACS/anti-platelet use, history of IS/deceleration time, and history of ICH/warfarin use. The areas under the curve of the developed models for each event were 0.900, 0.912, 0.879, 0.758, and 0.753, respectively.

CONCLUSION

Here, we described our experience with the development of models for predicting cardiovascular prognosis by machine learning. Machine learning could identify risk predicting models with good predictive capability and good discrimination of the risk impact.

Retrograde parallel wire technique using a dual lumen catheter can be useful for percutaneous coronary intervention with chronic total occlusion

The patient was a 61-year-old male with chronic total occlusion (CTO) of the right coronary artery (RCA). We performed percutaneous coronary intervention (PCI) to RCA-CTO with the bidirectional approach via the left anterior descending artery. In retrograde approach, the first wire entered the false lumen at the segment of severe stenosis of the CTO distal site. We performed parallel wire technique using a dual lumen catheter to avoid branch loss and succeeded to get the proximal true lumen through the second wire. When the first wire enters the false lumen, continued advancement of this wire easily should be avoided as it can collapse the true lumen and make reentry difficult. On top of that, in retrograde approach, it is difficult to perform parallel wire technique without using a dual lumen catheter. This case reveals that retrograde parallel wire technique using a dual lumen catheter is an extremely effective strategy to treat CTO. <Learning objective: The dual lumen catheter is one of the most helpful devices. However, in the field of percutaneous coronary intervention for chronic total occlusion (CTO-PCI), especially retrograde approach, the usage of them has not been established. Retrograde parallel wire technique using a dual lumen catheter may be useful for CTO-PCI.>.

Prognostic value of the heart rate profile during exercise in patients with atrial fibrillation

Aims

This study aimed to investigate the correlation of heart rate profile during exercise with exercise capacity and heart failure occurrence in patients with atrial fibrillation compared with patients with sinus rhythm.

Methods

We analyzed 2231 patients (atrial fibrillation: n = 321, sinus rhythm: n = 1910) who underwent a symptom-limited maximal cardiopulmonary exercise test at our institute. Their heart rate profile during exercise was assessed using peak heart rate and chronotropic response; (peak heart rate−resting heart rate)/(220−age−resting heart rate). The endpoint was the occurrence of heart failure events, defined as hospitalization for heart failure or heart failure-related death.

Results

There were significant positive correlations of peak heart rate and chronotropic response to peak oxygen consumption, both in atrial fibrillation and sinus rhythm. During a median follow-up period of 1262 (interquartile range 974–2921) days, 117 (5.2%) heart failure events were observed. Multivariate analyses showed that peak heart rate and chronotropic response were statistically significant predictors of heart failure events both in atrial fibrillation (peak heart rate: heart rate 0.975, p = 0.002, chronotropic response: heart rate 0.196, p = 0.003) and in sinus rhythm (peak heart rate: heart rate 0.988, p = 0.036, chronotropic response: heart rate 0.347, p = 0.020). Bivariate models showed that compared with chronotropic response, peak heart rate was a stronger predictor of heart failure in atrial fibrillation, whereas the finding was reversed in sinus rhythm.

Conclusion

The exercise- heart rate profile was significantly related to exercise capacity and future heart failure events, regardless of rhythm. However, the impacts of peak heart rate and chronotropic response on the endpoint varied according to the cardiac rhythm.

Relationship between the prognostic value of ventilatory efficiency and age in patients with heart failure

Background

Ventilatory efficiency decreases with age. This study aimed to investigate the prognostic significance and cut-off value of the minute ventilation/carbon dioxide production (VE/VCO2) slope according to age in patients with heart failure.

Methods and results

We analysed 1501 patients with heart failure from our observational cohort who performed maximal symptom-limited cardiopulmonary exercise testing and separated them into three age groups (≤55 years, 56–70 years and ≥71 years) in total and according to the three ejection fraction categories defined by European Society of Cardiology guidelines. The endpoint was set as heart failure events, hospitalisation for heart failure or death from heart failure. The VE/VCO2 slope increased with age. During the median follow-up period of 4 years, 141 heart failure (9%) events occurred. In total, univariate Cox analyses showed that the VE/VCO2 slope (cont.) was significantly related to heart failure events, while on multivariate analysis, the prognostic significance of the VE/VCO2 slope (cont.) was poor, accompanied by a significant interaction with age ( P < 0.0001). The cut-off value of the VE/VCO2 slope increased with the increase in age in not only the total but also the sub-ejection fraction categories. Multivariate analyses with a stepwise method adjusted for estimated glomerular filtration rate, peak oxygen consumption, atrial fibrillation and brain natriuretic peptide, showed that the predictive value of the binary VE/VCO2 slope separated by the cut-off value varied according to age. There was a tendency for the prognostic significance to increase with age irrespective of ejection fraction.

Conclusion

The prognostic significance and cut-off value of the VE/VCO2 slope may increase with advancing age.

Insulin degludec overdose may lead to long-lasting hypoglycaemia through its markedly prolonged half-life

BACKGROUND

Overdose of insulin often causes long-lasting severe hypoglycaemia. Insulin degludec has the longest duration of action among the available insulin products; thus, an overdose of insulin degludec can lead to long-lasting hypoglycaemia. In the present paper, we report the case of a woman with long-lasting hypoglycaemia attributable to insulin degludec overdose and markedly prolonged insulin degludec half-life.

CASE REPORT

A 64-year-old woman with Type 2 diabetes receiving insulin therapy was taken to an emergency department because of disturbed consciousness 21 h after self-injection of 300 units of insulin degludec (4.34 units/kg). Her plasma glucose level was 2.3 mmol/l. She received repeated intravenous boluses of dextrose for 43 h with continuous intravenous dextrose infusion, but no improvement in long-lasting hypoglycaemia or consciousness was observed. Considering the possibility of adrenal insufficiency, intravenous dexamethasone was administered, and her plasma glucose levels subsequently remained above 5.5 mmol/l without intravenous dextrose boluses. She gradually regained consciousness. A total of 34 h after the overdose, her plasma immunoreactive insulin levels were markedly increased and then gradually declined over ~400 h. The insulin degludec half-life was 40.76 h.

CONCLUSION

Although the reported half-life of insulin degludec in the body is ~25 h when administered in standard doses (0.4-0.8 units/kg), no study has investigated its half-life after overdose. In the present case, the half-life of insulin degludec was ~1.6 times longer than that observed with standard doses, probably leading to long-lasting hypoglycaemia. Physicians should be aware of the possibility of unexpected long-lasting severe hypoglycaemia resulting from insulin degludec overdose.

Efficacy of biolimus A9-eluting stent for treatment of right coronary ostial lesion with intravascular ultrasound guidance: a multi-center registry

The aim of this study was to assess the efficacy of a biolimus A9-eluting stent in patients with a right coronary artery (RCA) ostial lesion. Ostial lesions of the RCA have been a limitation of percutaneous coronary intervention even in the drug-eluting stent (DES) era. However, clinical outcomes after the deployment of a second generation DES to an RCA ostial lesion with intravascular ultrasound (IVUS) guidance have not been fully elucidated. From September 2011 to March 2013, 74 patients were enrolled in 17 centers from Japan. RCA ostial lesion was defined as de novo significant stenotic lesion located within 15 mm from ostium. IVUS was used for all cases to confirm the location of ostium and evaluate stent coverage of ostium. Patients with hemodialysis were excluded. The primary endpoint is a major adverse cardiac event (MACE) at 1 year. Forty two percent of patients had multi-vessel disease. Angiographically severe calcification was observed in 26% of the lesions. The mean stent diameter was 3.3 ± 0.3 mm (3.5 mm, 72%, 3.0 mm, 25%, and 2.75 and 2.5 mm, 3%), stent length was 17.5 ± 5.8 mm, and dilatation pressure of stenting was 15.6 ± 4.1 atm. RCA ostium was covered by stent in all lesions in IVUS findings. Post dilatation was performed for 64% of lesions (balloon size 3.7 ± 0.6 mm). MACE rate at 1 year was 5.4% (target lesion revascularization 5.4%, myocardial infarction 1.2%, and no cardiac death). The biolimus A9-eluting stent for RCA ostial lesions with IVUS guidance showed favorable results at 1-year follow-up.

Incidence and impact on midterm outcome of intimal versus subintimal tracking with both antegrade and retrograde approaches in patients with successful recanalisation of chronic total occlusions: J-PROCTOR 2 study

AIMS

The aim of this study was to assess the incidence and impact on midterm outcomes of intimal versus subintimal tracking with both antegrade and retrograde approaches in patients undergoing successful percutaneous coronary intervention for chronic total occlusion (CTO).

METHODS AND RESULTS

In 2012, a total of 1,573 CTO cases from 30 hospitals were enrolled in the Japanese CTO registry. Successful guidewire crossing was performed in 1,411 cases (89.7%). Among them, the guidewire penetration position was clearly identified using intravascular ultrasound (IVUS) imaging in 352 cases, and clinical follow-up at 12 months was performed in 323 cases. These 323 cases were enrolled in this retrospective study: 242 cases were treated with the antegrade approach (antegrade group) and 81 cases were treated with the retrograde approach (retrograde group). The endpoint of this study was target vessel revascularisation (TVR) and major adverse cardiac events (MACE) at 12-month follow-up. Subintimal tracking occurred more frequently in the retrograde group (11.6% vs. 30.9%, p<0.01). TVR was more frequent in the subintimal tracking group in the retrograde group (7.1% vs. 16.0%, p=0.03) but not in the antegrade group (2.8% vs. 3.6%, p=0.99). Although the occlusion length was similar, the subintimal tracking group required a longer stent length compared to the intimal tracking group in the retrograde approach (59.7±24.4 mm vs. 74.0±24.4 mm, p<0.01).

CONCLUSIONS

Subintimal tracking was more frequent in the retrograde approach. Intimal tracking should be recommended in the retrograde approach to reduce stent length and to improve follow-up outcomes.